This invention relates to apparatuses and systems used to drill holes in plastic pipelines that transport natural gas. More particularly, the invention allows an operator to use the same tool to tap and pressure test the pipeline and to gauge and purge the pressure within the pipeline.
In the conventional process, a replacement pipeline is attached to the section of the original pipeline that is to be abandoned. The operator then uses a high volume “T” punch tool to tap the original pipeline at a point where the original and replacement pipelines intersect. Next, the replacement pipeline is purged through a hole located near the opposite end of the replacement pipeline. The punch tool is then used to tap the original pipeline at the other point where the original and replacement pipelines intersect. Two pressure gauges are installed on the original pipeline, one near each point where the pipeline has been tapped and on the opposite side of the section of original pipeline that is to be abandoned. The operator then squeezes off the section of pipeline between the two taps that is to be abandoned, gauges it to make sure that there is no pressure loss, and purges it. The next step is to cut that section of pipeline, with the cuts located near the squeeze-offs and on the opposite side of the taps. The open ends of the pipeline are then capped to complete the relocation. This process requires about thirteen steps. The process also requires separate tools for tapping, gauging, and purging the pipeline and that the original and replacement pipelines be tapped, purged, or gauged at six different locations.
There is a need for a single tool that can be used to tap the pipeline and to gauge and purge the pressure within the pipeline. This allows the operator to relocate a section of pipeline using fewer steps and less equipment and parts, thereby reducing the time required for each relocation as well as the associated costs. In addition, the total number of tools an operator must carry is reduced, further improving efficiency and reducing the cost of operations, maintenance, and repair.